如何围绕我在地图上单击或搜索的任何点创建一个圆圈？我不想在标记周围创建一个预定义的半径

Question

下面的代码是创建圆圈的示例 API，我可以如何调整代码以响应点击而不是围绕预定义标记创建圆圈。请看下面： https://developers.google.com/maps/documentation/javascript/examples/circle-simple

    <script>
      // This example creates circles on the map, representing populations in North
      // America.

      // First, create an object containing LatLng and population for each city.
      var citymap = {
        chicago: {
          center: {lat: 41.878, lng: -87.629},
          population: 2714856
        },
        newyork: {
          center: {lat: 40.714, lng: -74.005},
          population: 8405837
        },
        losangeles: {
          center: {lat: 34.052, lng: -118.243},
          population: 3857799
        },
        vancouver: {
          center: {lat: 49.25, lng: -123.1},
          population: 603502
        }
      };

      function initMap() {
        // Create the map.
        var map = new google.maps.Map(document.getElementById('map'), {
          zoom: 4,
          center: {lat: 37.090, lng: -95.712},
          mapTypeId: 'terrain'
        });

        // Construct the circle for each value in citymap.
        // Note: We scale the area of the circle based on the population.
        for (var city in citymap) {
          // Add the circle for this city to the map.
          var cityCircle = new google.maps.Circle({
            strokeColor: '#FF0000',
            strokeOpacity: 0.8,
            strokeWeight: 2,
            fillColor: '#FF0000',
            fillOpacity: 0.35,
            map: map,
            center: citymap[city].center,
            radius: Math.sqrt(citymap[city].population) * 100
          });
        }
      }
    </script>`enter code here`
    <script async defer
    src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap">
    </script>

Answer 1

假设地图是你 google 地图对象你可以这样添加地图点击事件

   google.maps.event.addListener(map, "click", function () {

        cityCircle = new google.maps.Circle({
        strokeColor: '#FF0000',
        strokeOpacity: 0.8,
        strokeWeight: 2,
        fillColor: '#FF0000',
        fillOpacity: 0.35,
        map: map,
        center: citymap[city].center,
        radius: Math.sqrt(citymap[city].population) * 100
      });

    });